Telegraphy.



N'o.848,221. I PATENTEDMAR.26,1907.

' J. 0. BARCLAY.

TELEGRAPHY. "APPLICATION FILED mums, 190s.

lllllllll] INVENTOR I UNITED STATES PATENT @FFIQE.

TELEGRAPHY.

Specification of Letters Patent.

Patented March 26, 1907.

Application filed March 19,1906. Serial No. 306,792.

To all 11/71071 it may concern):

Be it known that I, JOHN C. BARCLAY, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Telegraphy; and Ido hereby declare the following to be a full, clear, and exactdescription of the same, such as will enable others skilled in the artto which it appertains to make and use the same.

My invention relates to quadruplex and diplex telegraphs, andparticularly to that class thereof wherein two messages in the samedirection are transmitted by current pulses of different polarity. Insuch systems certain advantages are gained by operating the system, ormore properly supplying cur rent to the system, by means of analternating-current generator, suitable distributing means beingemployed, so that all of the posi' tive pulses from such generator passto one of the two transmitters only and all of the negative pulses fromsuch generator pass to the other of such two transmitters only; butheretofore where a plurality of diplex or quadruplex lines were to beoperated it has been. found impracticable to supply current to all or aplurality of such lines from a single alternating-current generator,owing to occasional mutilation of signals in one circuit or the Itransmission of false signals therein, due to formation of a derivedcircuit upon simultaneous operation of the other transmitter of the samecircuit and of the transmitter of another circuit from the samegenerator, whereby a current pulse may be sent through one of the lineswhen the corresponding trans mitter is open. The inconvenience andexpense of providing a separate generator for each line, as heretoforerequired to avoid the formation of false derived circuits, as mentioned,has militated greatly against the adoption of diplex and quadruplexsystems of the alternating-current type.

My invention consists in means whereby the formation of such derivedcircuits and consequent interference with transmission in one line bytransmission in another line connected to the same generator is obviatedand whereby any desired number of lines may be operated from the samegenerator with out interference with messages transmitted through any ofsuch circuits by transmission in any of the other circuits.

The object of my invention is to supply current for any desired numberof dipleX or quadruplex lines of the class described from a commongenerator, and to do this by simple, inexpensive, and entirely reliablemeans.

In the accom anying drawing I illustrate diagrammaticalfy one form ofapparatus and one arrangement of circuits whereby such object isaccomplished. Said drawing shows transmitting and receiving instrumentsat one end of each of two quadruplex telegraphlines, together with asingle alternating-current generator and means whereby current issupplied to both said lines from said common generator entirely withoutinterference such as mentioned.

In the said drawing, two line-wires 1 1 are shown. The transmitting andreceivin apparatus for these lines are identical, and therefore the saidapparatus of only one of the lines need be described, the instrument andapparatus for line 1 being designated by the same reference charactersused for corresponding parts ofline 1 with letter a added.

For line 1 there are transmitters 2 and 3 of ordinary type, eachcontrolled by an ap propriate hand-key and local circuit. The particulartransmitter, indicated are of the Walking-beam type, the backcontact-stop 4 of each transmitter being connected to a ground-brush ofthe generator, as herein after described, and thence to ground, thefront contact-stop 5 of one transmitter being connected to brush 6 ofthe transmittinggenerator and the front contact-stop of the othertransmitter being connected to brush 7 of such generator. The armatures8 of the transmitters are connected to the line conductor throughcommutating devices operated in synchronism with the generator, ashereinafter described.

9 designates the armature of an alternating-current transmitter, 10 thefield-magnet thereof, and 11, 12, and 13 designate distributing-ringsmounted on practice rotates in synchronism with the armature 9 and maybe understood to be the armature-shaft, although for simplicity andclearness of illustration the diagram does not show a driving connectionbetween the armature and said shaft. I have not indi cated means fordriving the armature 9 and shaft 14, as any means suitable for suchpurpose may be employed; neither have I inclicated any particular typeof field-winding, and it will be understood that any suitable a shaft14, which in windin may be employed for the winding of the field-coilsor for the armature as well. The particular dynamo indicated is afourpole dynamo; but this is immaterial, all that is necessary beingthat there shall be proper correspondence between the poles of thefield-magnets and the segments on the selecting-rings and commutators.

The generator having four poles, distributer-rings 11 and 12 are eachdivided into four segments 15, 16, 17, and 18, of which. 15 and 17 ofring 11 are connected electrically and 16 and 18 of ring 12 areconnected electrically, segments 16 and 18 of ring 11. and segments 15and 17 of ring 12 being out of electrical connection and therefore idle.

I have shown brushes 6 and 7 for rings 11 and 12, respectively, brush 6passing into contact with a live section of its distributingring 11 asbrush 7 of ring 12 passes out of contact with a live section and intocontact with a dead section of its ring 12. The ground-ring 13 is notdivided into segments, but is connected to round (a term which I employenerically for all forms of return) by brus 21. The armature-coils ofthe generator are connected to the live segments 1.5 and 17 of ring 11to the live se ments 16 and 18 of ring 12 and to the groun ring 13, sothat when any one of the transmitters has its front contact closed acircuit is completed from ground through ring 13, thegenerator-armature, the distributing-ring corresponding to thattransmitter, and thence (as will be shown hereafter) through theappropriate commutating device to the line and thence to ground.

For convenience of description it may be assumed that transmitter 2controls only positive pulses and transmitter 3 controls only negativepulses. It will be seen that transmitter 2 is connected, through thedistributing ring 11, to the generator only when that generator isproducing a positive pulse and that transmitter 3 is connected, throughthe distributing-ring 12, to the generator only when that generator isproducing a negative pulse, and that during each period of connection ofa transmitter to its generator the current (supposing the line-circuitto be complete) rises gradually from zero to a maximum and then falls tozero gradually, this being the ideal condition for reducing to a minimumchoking in the telegraph instruments and inductive interference withother lines.

As stated above, heretofore it has not been practicable to operate morethan one circuit from a single generator in systems of the classdescribed owing to mutilation of signals or mutual interference betweensignals in the different circuits. That such is the case may be seenfrom the drawing, in which I have shown two line conductors 1. and 1,the circuits and instruments of circuit 1 being l l l 1 identical withthose of circuit 1 and being designated by the same reference characterswith the letter a added. to each for convenience in distinction.Supposing, therefore, that circuits 1 and 1 both take current from thesame generator, as is the case with the connections shown, and that thecommutating devices 22 and 22 are omitted, in which case the armatures 8of transmitters 2 and 3 will be connected directly to line 1, and thearmatures 8 of transmitters 2 and 3 will be connected directly to theline 1 and supposing that the front contact 5 of transmitter 2 is openand that the corresponding front con tacts of transmitters 3, 2*, and 3are allclosed, may well happen at one time, then there is a derivedcircuit from brush 6 through transmitter 2 to line 1., thence throughtransmitter 3 brush 7, and transmitter 3 to line 1., the effect of whichderived circuit is the same as though transmitter 2 were closed, whichis not the case. To obviate this mutual interference between thetransmitters of different lines operated from 'the same generator, Iprovide commutating devices 22, 22 and so on, one for each line operatedfrom the common generator driven in synchronism with thegenerator-armature and distributing-rings 11, 12, and 13 and preferablyon the same shaft. In the simple form shown in the drawings each suchcommutating device comprises a disk having insulated or dead segments 23corresponding to the dead segments of the distributing-rings 11 and 12,the remainder of the surface of such disk being conductive, and Iprovide in connection with each such disk a brush 2%, to which thearmature of which the armature of transmitter 3 is connected, (saidbrushes arranged to track over the live and dead sections of the diskalternately and spaced apart by an angle corresponding to the arc ofsuch dead sections) and a brush 26, connected to the line and trackingonly on the live portion of the disk. It will be seen that when thesecommutating devices are used a transmitter 3 is never connected. to theline when the corresponding transmitter 2 is connected to the line, andvice versa, and therefore the possibility of false signals or mutilationof signals in the manner above explained is entirely avoided, thusmaking possible the operation of any desired number of circuits from thesame generator.

The particular receiving apparatus I have shown in the drawing is thatcommonly employed in systems of the class described, comprisingline-relays 27 and 28, one polarized to respond only to positive pulsesand the other to respond only to negative pulses, repeating-relays 29and 30 for said line-relays, and sounders 31 and 32. The line-relays aredifferentially wound for the line 1 and artitransmitter 2 is connected,a brush 25, to I ficial line 1, as is customary in duplex and quadruplexsystems.

The operation of the apparatus is as follows: The generator,distributing, and commutating devices being in full operation, brush 6connects the generator to stop of transmitter 2, while a positive pulseproduced by said generator rises and then falls, brush being at suchtime on a dead section of commutating-disk 22 and brush 24 on a livesection thereof, so that armature 8 of transmitter 2 is connected to theline and armature S of transmitter 3 is disconnected from the line, andthe same is true with respect to transmitters 2 3 and line 1 hen thepositive pulse has nearly died down, the transmitter 2 is disconnectedfrom the generator and line and at the beginning of the next negativepulse stop 5 of transmitter3is connected to the generator through brush7, and the armature 8 of transmitter is connected to the line throughbrush 25. The pulses succeed each other with great rapidity, so thateven a dot of the Morse code will include enough of the correspond ingpulses (positive or negative,'as the case may be) to cause the operationof the correspondingly-polarized receiving-relay at the distant station.

that I claim is 1. In a telegraph system, the combination with aplurality of transmitting sets for different lines, each set comprisingtwo transmitters, for currents of different polarity respectively, meansfor supplying an alternating current, and distributing means controllingthe supply of current therefrom to said transmitters, of means forpreventing mutual interference with transmission by one of saidtransmitting sets through simultaneous operation of instruments ofanother of said transmitting sets.

2. In a telegraph system, the combination with a plurality oftransmitting sets for dif ferent lines, each set comprising twotransmitters, for currents of different polarity respectively, analternating-current generator, and distributing means controlling thesupply of current therefrom to said transmitters, of means forpreventing mutual interference with transmission by one of saidtransmitting sets through simultaneous operation of instruments ofanother of said transmitting sets.

3. In a telegraph system, the combination with a plurality oftransmitting sets for different lines, each set comprising twotransmitters, for currents of difierent polarity respectively, means forsupplying an alter nating current, and distributing means controllingthe supply of current therefrom to said transmitters, of commutatingmeans for each set of such transmitters, operated synjchronously withthe distributing means,

and comprising means which disconnects each transmitter of thecorresponding set from its line during transmission through such line ofcurrent of polarity opposite to that controlled by the transmitter sodisconnected.

4. In a telegraph system, the combination with a plurality oftransmitting sets for different lines, each set comprising twotransmitters, for currents of different polarity respectively, analternating-current generator, and distributing means controlling thesupply of current therefrom to said transmitters, of commutating meansfor each set of such transmitters, operated synchronously with thegenerator and comprising means which disconnects each transmitter of"the corresponding set from its line during transmission through suchline of current of polarity opposite to that controlled by thetransmitter so disconnected.

5. In a telegraph system, the combination with a plurality oftransmitting sets for different lines, each set comprising twotransmitters, for currents of diiierent polarity respectively, of analternating-current generator, distributing means controlling the supplyof current therefrom to said transmitters, and commutating means foreach set of such transmitters operated synchronously.

6. In a telegraph system, transmitting means comprising in combinationan alternating-current generator, distributing means operatedsynchronously therewith and arranged to direct positive pulses through acircuit of one of two transmitters and negativepulses through a circuitof the other of such transmitters, and commutating means likewiseoperated synchronously with the generator and comprising means fordisconnecting each of such transmitters from the line during theproduction by such generator of a current pulse of the directionopposite that to which the transmitter so disconnected corresponds.

In testimony whereof I affix my signature in the presence of twowitnesses.

JOHN C. BARCLAY. Witnesses:

H. M. MARBLE, C. A. VAN BRUNT.

